The Earth’s rotation is accelerating, and it just broke a record

This imperceptible trend for the general public is not always easy to manage for network administrators.

This is a detail that may surprise some, but the speed of the Earth’s rotation is not completely fixed; it varies greatly over time. On June 29, in an article seen by Popular Mechanicsresearchers from the National Physical Labs (NPL) announced that this day is the shortest on record since the invention of the atomic clock in the 1960s.

This measurement is based on records from the International Earth Toration and Reference Systems Service (IERS). It is an institution that takes care of collecting, validating and redistributing a lot of data on the Earth’s rotation and orientation.

Very different trends in the short and long term

As a general rule, if we reason on very long time scales, beyond human life, the rotation of our planet will slow down a little. This is only a well-known consequence of its gravitational interaction with the Moon and Sun. A article published in a prestigious magazine Science explains for example that the rotation of our cradle has has slowed down by about 6 hours in the last 2740 years.

But IERS calculations show that the short-term trend is very different, and even diametrically opposed. June 29 was cut by 1.59 milliseconds compared to the generally accepted 24 hours. And this is not an isolated event. According to the special site, this record has already been broken 28 times in 2020, with an estimated lag of -1.47ms. This dynamic has continued to increase since then, with new surveys of -1.50ms on the 26th June, then on -1.59 ms three days ago. These values ​​are compiled in the graph below.


It describes very well the variability of this parameter, but also the trend it is currently following in our scale; despite annual and seasonal variations, obviously the average length of the day has decreased over the years – and so the Earth spins faster and faster.

A still poorly understood phenomenon

The origin of this strange difference remains to be explained… and for now, researchers are still skeptical. Even experienced geologists exchange guesses on the fly on Researchgate, a portal very popular among researchers.

Some suggest it may be a consequence of Earth’s internal geodynamics. Others believe that it is necessary instead to be interested in its orbit and its relationship with neighboring celestial bodies to complete this file. But for now, it still doesn’t exist there is no consensus.

But while the question is clearly worth asking, the answer is not particularly important outside the framework of basic research. The consequences of these gear changes, on the other hand, are even greater.


In fact, to compensate for the effect of the long-term slowdown described at the beginning of the article, the international community agreed to introduce a system of ” leap seconds “. Since 1972, 27 seconds have been added to the universal standard, Coordinated Universal Time.

This method has worked well so far; but if the rotation of the Earth accelerates too much, this sleight of hand may become a problem. In fact, many specialists believe that at this time it is necessary to introduce a “negative leap second” to slow down this recent acceleration. A prospect that already scares some professionals

Concrete consequences for networks

The problem is that time management is an absolutely essential component of modern networks. These are usually based on so-called “timestamps”, types of virtual buffers that confirm the date and time of an operation.

If these timestamps are wrong, then it can cause many problems for synchronization, authentication, archiving, and more. The Windows Server documentation has a dedicated page to support this issue.

© Igor Anak – Unsplash

In a blog post, two Meta employees gave their point of view on the matter. They explain that whenever one of these leap seconds is introduced, engineers and system administrators face this type of problem. ” They have caused problems throughout the industry and continue to present many risks “says the authors of the post.” It harms the community every time “, they lamented.

So the authors argue in favor of a definitive locking of the current 27 leap seconds. They also explain that it is more appropriate to find a new system that will be possible to compensate for these changes without changing all the computer systems. It is therefore interesting to observe how the industry responds to this problem and follows the evolution of the Earth’s rotation speed.

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